JP2001113618A - Heat insulating material and method for its preparation - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a heat insulating material with excellent heat insulating properties. SOLUTION: A heat insulating material formed of two sheets of resin films prepared by laminating a flat resin film A and an embossed resin film B wherein (1) a resin film whose energy absorbing ratio to black-body radiation at 0-100 deg.C is at most 0.1 is used, (2) heights of projections of emboss processing of the film B are 1-10 mm, (3) a gas is filled in the projections of the emboss processing of the film B, (4) aluminum is deposited on the outer surface of the film A and (5) energy reflectance to black-body radiation at 0-100 deg.C of the inside surface of the film A after deposition of aluminum is at least 0.85, is provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a heat insulating material and a method for manufacturing the same.

[0002]

2. Description of the Related Art Conventionally, as a heat insulating material, a molded article containing glass fiber or ceramic fiber, or a molded article made of expanded polyethylene, expanded polystyrene, expanded polyurethane or the like has been used as a cylindrical shape or a sheet shape.
Their thermal conductivity was much higher than that of air without convection, and their insulation performance was not sufficient. In addition, soft materials are easily compacted when a force is applied during construction or use, and the heat insulation performance is greatly reduced. On the other hand, in the case of hard foam,
It is brittle and hard to deform, so it is easily broken. Furthermore, since the foaming agent is bulky, it is inferior in transportation efficiency when carrying a large amount of heat insulating material such as during construction. In the case where the heat insulating material is a molded body containing fibers, the fibers are easily broken off or come off from the material and are easily detached from the material.

On the other hand, a heat insulating material in which a flat resin film is adhered to one surface of an embossed resin film has a large radiant heat transfer and an insufficient heat insulating property. In order to improve heat insulation, it has been proposed that a flat resin film be attached to both surfaces of the embossed resin film, and further, that an aluminum-evaporated resin film be attached to the surface opposite to the surface having the embossed protrusions. However, in this case, it is difficult to deform, so it is difficult to apply a tight fit without wrinkles to other than a flat part (for example, a pipe). It was difficult.
In other words, when wrinkles occur, for example, when applied to a pipe in a building, a large number of portions having a small layer thickness are locally generated, and it is acceptable for a given space (often a narrow place). The problem is that the thickness of the heat insulating material is reduced, so that the heat insulating performance is reduced. Further, when the heat insulating material is used as a pipe for cold water, dew condensation easily occurs. Further, when such a heat insulating material is applied to the pipe, the inner resin film is drawn into the concave side of the embossing, and the air layer becomes thin, and the heat insulating property is undesirably reduced.

[0004]

SUMMARY OF THE INVENTION An object of the present invention is to provide a heat insulating material which does not have the above-mentioned disadvantages.

[0005]

SUMMARY OF THE INVENTION The present inventor has disclosed a heat insulating material in which a flat resin film is stuck on one side of an embossed resin film and aluminum is vapor-deposited on the surface of the flat resin film. Although it has a flat resin film only on the outside of the film, it has been found that it exhibits excellent heat insulating properties and eliminates the above-mentioned disadvantages, and thus completed the present invention.

That is, the present invention provides the inventions described in the following items.

Item 1 is a heat insulating material composed of two resin films in which a flat resin film (A) and an embossed resin film (B) are bonded, 1) Film (A) and film (B) And (2) a resin film having an energy absorption rate of 0.1 or less for black body radiation at 0 to 100 ° C. is used. 2) The height of the embossed projections of the film (B) is 1 to 1
0) 3) Gas is sealed in the embossed projections of the film (B), 4) Aluminum is deposited on the outer surface of the film (A), 5) Film (A) after aluminum deposition ) On the inside surface,
A heat insulating material having an energy reflectance of 0.85 or more with respect to blackbody radiation at 0 to 100 ° C.

Item 2 The heat insulating material according to Item 1, wherein aluminum is deposited on the outer surface of the film (B).

Item 3. The heat insulating material according to Item 1 or 2, wherein the enclosed gas is a gas containing at least one selected from the group consisting of carbon dioxide and fluorinated hydrocarbons.

Item 4 The thermal insulation according to any one of claims 1 to 3, wherein the material of the resin film is at least one selected from the group consisting of polyimide resin, polyester resin, polyamide resin, polyethylene resin and polyvinyl chloride resin. Wood.

Item 5 At least two of the heat insulating materials described in any one of Items 1 to 4 are used as one heat insulating film (A).
And a laminated heat insulating material for a tube, which is laminated so that the embossing of the film (B) of the other heat insulating material is in contact with the film, and the thickness direction so that both end surfaces are joined when applied to the pipe. A laminated heat insulating material for pipes, which is cut into gradually widened shapes.

Item 6. A heat insulating material for pipes formed by connecting both ends of the heat insulating material described in Item 5 into a cylindrical shape.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION A heat insulating material of the present invention comprises a flat resin film (A) which has not been subjected to a treatment such as embossing.
It is obtained by laminating an embossed resin film (B).

As the resin film (A) and the resin film (B), a resin film having an energy absorption rate of 0.1 or less, preferably 0.05 or less with respect to black body radiation at 0 to 100 ° C. is used. The resin film that satisfies the above condition of the energy absorption can be obtained by appropriately selecting the materials and thicknesses of the resin film (A) and the film (B) from the following conditions.

Examples of the material of the resin film include a polyimide resin, a polyester resin, a polyamide resin, a polyvinyl chloride resin, and a polyethylene resin. Polyimide resin such as polyetherimide resin; Polyethylene terephthalate (PE) as polyester resin
T) Resin, polybutylene terephthalate resin and the like; As the polyamide resin, a nylon resin is preferably exemplified.

As a material for the resin film (A) and the resin film (B), a material having low gas permeability is preferably used. When such a resin film is used, it is possible to seal the gas for a long period of time, and it is preferable to enclose a gas having a lower thermal conductivity than air since the durability of the heat insulating performance is improved. As a resin film having low gas permeability, for example, a gas at the time of drying (enclosed gas)
What transmittance of about less than ^{10ml / (m 2 · 24h ·} atm) are preferred, more preferably of about less than ^{3ml / (m 2 · 24h ·} atm), 1ml / (m 2 · 24h · a
tm) are more preferred.

It is preferable to make the resin film flame-retardant because fire is unlikely to occur. The flame retardation of the resin film can be performed, for example, by mixing a flame retardant such as boric acid or sodium borate at the time of film formation.

The material type of the flat resin film (A) that has not been embossed and / or the material of the resin film (B) that has been embossed may be different but are preferably the same.

The thickness of the resin film is not particularly limited as long as it does not break during molding or use, and is appropriately determined according to the thermal conductivity of the material used, the distribution density of embossing, and the like. The thickness can be set, but the thickness is preferably such that the amount of heat transfer by the resin film is about 10% or less, preferably about 5% or less of the amount of heat transfer by the enclosed gas, and usually about 50 μm or less. And more preferably about 3 to 40 μm.

The embossing can be carried out according to a commonly used method, for example, by a press using a pressure roll or a molding die.

It is preferable that the embossing (the protrusion formed by the embossing) is uniformly (uniformly) applied to the resin film without bias. If the embossing is applied uniformly, the uniformity of the thickness of the heat insulating material, the uniformity of the deformation when a load is applied (the uniformity of the thickness), and the uniformity of the load are ensured. This is preferable because the resin film is hardly damaged. The embossing is preferably performed, for example, in an amount of about 0.3 to 10 per 1 cm ² .

The height (height of unevenness) of the projections in the thickness direction of the embossed resin film (B) is about 1 to 10 mm, and preferably about 2 to 8 mm. 1m
If it is less than m, the number of layers when laminated to increase the thickness of the heat insulating material necessary for obtaining the desired heat insulating performance increases, and the cost increases, which is not practical. If it exceeds 10mm,
In a closed space formed by the resin film (A) and the resin film (B), heat transfer due to convection of gas increases, which is not preferable because heat insulation performance is reduced.

Examples of the shape of the embossing include a columnar shape, a hemispherical shape, and a rectangular parallelepiped shape. The area of the emboss in the horizontal direction of the resin film is 0.1 to 3c.
It is preferably about m ² .

An embossed resin film (B);
A flat resin film (A) that has not been embossed
As shown in FIG. 1- (1) and FIG. 1- (2), they are bonded to each other. The bonding is performed using, for example, an adhesive. The type of the adhesive is not particularly limited, and can be appropriately selected from commonly used adhesives according to the type of the resin film. Alternatively, the resin film (A) and the resin film (B) may be bonded by heat fusion. Heat fusion can be performed according to a conventional method, and the temperature at that time can be appropriately set according to the type of the resin film, and is usually about 80 to 300 ° C.

The bonding of the resin film (A) and the embossed resin film (B) may be performed continuously or in a batch system. However, resin film
(A) and the resin film (B) are preferably continuously supplied to a molding machine from the viewpoint of working efficiency.

When the resin film (A) and the resin film (B) are bonded together, a space (hereinafter, referred to as a “cell”) may be formed by the projections of the embossed resin film (B) and the resin film (A). ) Is formed, and when the space is bonded so as to form a cell having airtightness, gas can be sealed. Since the gas-filled cell with airtightness is hardly compressed when a load is applied, the thickness of the heat insulating material hardly changes, and the deterioration of the heat insulating performance can be suppressed to a very small extent.

As the gas to be filled in the cell, air or a gas having a lower thermal conductivity than air is preferable. These can be encapsulated alone or in combination. Preferred examples of the gas having a lower thermal conductivity than air include carbon dioxide and fluorinated hydrocarbons (for example, fluorinated hydrocarbons having about 1 to 3 carbon atoms such as methyl fluoride, ethyl fluoride and propyl fluoride). Is done. It is preferable to seal a gas having a lower thermal conductivity than air, since a heat insulating material having better heat insulating performance can be obtained.

When a gas having a lower thermal conductivity than air is sealed, it is desirable to use a resin film having an extremely low transmittance for the gas.

The amount of gas to be charged can be appropriately set according to the type of gas, desired heat insulating properties, and the like, but is usually such that the pressure in the cell becomes approximately atmospheric pressure.

In the heat insulating material of the present invention, aluminum is deposited on the outer surface of the resin film (A). Since aluminum has a low emissivity, a heat insulating material on which aluminum is deposited significantly reduces radiant heat transfer and greatly improves heat insulating performance. For example, as shown in FIG. 1, aluminum deposition can be performed according to a commonly used method after laminating the resin film (A) and the resin film (B).
Alternatively, aluminum may be previously vapor-deposited on one side of the flat film (A), and the other side of the resin film (A) may be bonded to the resin film (B). Aluminum deposition is preferably mirror-finished using conventional methods,
Alternatively, it is preferable to finish the metal surface with few oxide films.

Aluminum is deposited by black body radiation of 0 to 100 ° C. on the inner surface of the resin film (A) (the surface of the resin film (A) opposite to the surface on which aluminum is deposited) in the state where aluminum is deposited. Is performed so that the energy reflectance with respect to is 0.85 or more, preferably 0.9 or more, and more preferably 0.95 or more. Such reflectivity is
For example, it can be obtained by appropriately setting the thickness of aluminum deposition, for example, by setting the thickness of aluminum deposition to 0.03 μm or more. The upper limit of the thickness of the aluminum vapor deposition is not particularly limited, but is usually about 5 μm.

In the heat insulating material of the present invention, it is preferable that aluminum is also deposited on the outer surface of the embossed resin film (B) (the surface having the embossed protrusions). FIG. 2 shows a conceptual diagram of the heat insulating material of the present invention in which aluminum is deposited on the outer surface of the resin film (B). When aluminum is deposited on the outer surface of the resin film (B),
Even if a heat insulator is applied so that the resin film (B) is in contact with the surface with high emissivity, the radiation from the outer surface of the resin film (B) (the surface not bonded to the resin film (A)) is reduced. It is preferable because it becomes possible. Also in this case, it is preferable to finish the deposition of aluminum on a mirror surface or in a metal state with a small oxide film on the surface.

The single-layer heat insulating material thus obtained (FIG. 1)
(3)) uses at least two pieces of heat insulating material, and the flat film (A) of one piece of heat insulating material and the embossed protrusions (cells) of the other piece of film (B) of heat insulating material are used. Lamination is performed so as to be in contact with each other to form a laminated heat insulating material.

The number of layers and the thickness of the resin film of the laminated heat insulating material are not particularly limited as long as the desired heat insulating performance according to the application is obtained, but the height of the embossed projections and the application of the heat insulating material are not limited. (Use place) and the like can be appropriately set, for example, about 2 to 10 layers,
It is preferably about 00 mm.

The laminated heat insulating material may be a single layer heat insulating material or a flat film of one heat insulating material (A) and a film of the other heat insulating material (B). May be bonded to the embossed projection using a commonly used adhesive.

At the time of lamination, the embossed portions of the respective layers may be laminated so as to overlap, or may be laminated so as not to overlap.

The heat insulating material (single layer type and laminated type) of the present invention
It can be preferably used for applications such as construction and air conditioning. For architectural purposes, for example, it can be applied to wall surfaces, ceilings, floors, etc., and specifically, it can be used for wall heat insulation, floor heating, and the like. For air conditioning, it is suitable as a working medium of a heat source unit for air conditioning or a pipe for transferring cold or hot heat. The heat insulating material of the present invention is also suitable as a heat insulating material for a tubular tank for storing cold and hot heat.

When the heat insulating material of the present invention is applied to a pipe, it is preferable to wind the resin film (B) inside, that is, the surface with the embossed protrusion inside.

When applying a single-layer type heat insulating material to a pipe, it is usually preferable to wind the pipe in a roll shape because wrinkles hardly occur.

When a laminated heat insulating material is used as a heat insulating material for a pipe, in order to make it possible to adhere the pipe without wrinkles, it is necessary to apply the heat insulating material in the thickness direction so that both end faces are joined when the pipe is applied. It is preferable to cut the sheet into a gradually widened shape. More specifically, each layer is gradually cut in the thickness direction so that the length in the width direction of the layer is about a circumferential length having a radius from the center of the pipe when applied to the pipe. This makes it possible to prevent the occurrence of wrinkles when applied to the pipe. The length in the width direction of each layer only needs to be widened so as not to cause wrinkles at the time of construction, and does not need to completely match the circumferential length. If wrinkles do not occur, it is preferable because the adhesion to the tube is improved and excellent heat insulating performance can be obtained in a smaller space. Fig. 3- (1) shows a conceptual diagram of such a heat insulating material, and Fig. 3- (2) shows a conceptual diagram of a pipe formed by applying the heat insulating material.
Shown in

Such a heat insulating material can be obtained by laminating single-layered heat insulating materials having the same length in the width direction, and then gradually cutting the heat insulating material so as to prevent wrinkles from occurring. Alternatively, a single-layered heat insulating material may be cut in advance into a length that gradually increases in width after being stacked, and then may be obtained by stacking them.

The heat insulating material for the pipe may be provided in a cylindrical shape. For example, if it is a laminated insulation material,
It may be formed by connecting both ends of a heat insulating material which is gradually cut into a wide shape so as not to cause wrinkles. The connection of both ends may be usually performed by applying an adhesive to both end surfaces, or may be performed by wrapping around a tube and fastening with an adhesive tape.

The present invention also includes pipes and tubular articles (for example, tubular tanks) provided with the above-mentioned various heat insulating materials.

[0044]

The heat-insulating material of the present invention has excellent heat-insulating properties, and is light in weight and can be made compact by roll winding, so that it is easy to store, transport and carry.

Further, according to the heat insulating material of the present invention, it is possible to perform wrinkle-free construction on a pipe or a tubular object, and to obtain excellent heat insulating performance.

[0046]

EXAMPLES The present invention will be described more specifically with reference to the following examples, but the present invention is not limited to these examples.

Example 1 A polyethylene resin film (thickness: 10 μm) having a height of 4
mm, 10mm diameter cylindrical embossing (projection)
Was provided at a density of 1 piece / cm ² (resin film (B)), and a flat polyethylene resin film (A) (thickness: 10 μm) was heat-sealed so that air was enclosed. When the energy absorption rate of the polyethylene resin film against blackbody radiation at 0 to 100 ° C was measured according to a conventional method, it was found that the value was 0.1%.
It was less than 05. Then, polyethylene resin film
Aluminum was deposited on the outer surface of (A) by a normal vacuum deposition method so as to have a mirror surface. The thickness of the aluminum layer was about 1 μm.

The energy reflectivity of the inner surface of the polyethylene resin film (A) after aluminum vapor deposition with respect to blackbody radiation at 0 to 100 ° C. was measured according to a conventional method and found to be 0.9 or more.

Three such single-layered heat insulating materials are prepared, and the embossed protrusions of the resin film (B) of another heat insulating material are overlapped with the resin film (A) of one heat insulating material. 3
The layers were stacked to form a laminated heat insulating material, and the effective thermal conductivity was measured.

For measuring the effective thermal conductivity, JIS-A1412 (19
An apparatus to which the flat plate heat flow method of 94) was applied was used. The sample size was 300 mm x 300 mm. The flat surface of the heat insulating material was 30 ° C., and the surface having the embossed projections was 10 ° C. The effective thermal conductivity is 0.029 W /
Km.

Example 2 A heat insulating material was obtained in the same manner as in Example 1 except that the filled gas was carbon dioxide. The effective thermal conductivity is 0.024 W / Km
Met.

Example 3 A heat insulating material was obtained in the same manner as in Example 1 except that the height of the embossed projections was changed to 6 mm. The effective thermal conductivity is 0.0
It was 29 W / Km.

Comparative Example 1 A heat insulating material was obtained in the same manner as in Example 1 except that aluminum was not deposited. Effective thermal conductivity is 0.051W / K
m.

Comparative Example 2 Example 1 except that the height of the embossed protrusion was 16 mm.
A heat insulating material was obtained in the same manner as described above. Effective thermal conductivity is 0.05
It was 1 W / Km.

Comparative Examples 3 to 6 The effective thermal conductivity of the current product (thickness: 20 mm) was measured under the same conditions as in Example 1. The results are as follows.

Comparative Example 3 Rockwool Insulating Plate 0.037 W / Km Comparative Example 4 Expanded Polyethylene Plate 0.042 W / Km Comparative Example 5 Glass Wool Insulating Plate 0.038 W / Km Comparative Example 6 Expanded Polystyrene Plate 0.038 W / Km The heat-insulating materials of the present invention obtained in 1 to 3 had smaller effective thermal conductivity than the heat-insulating materials of Comparative Examples 1 to 6, and exhibited excellent heat-insulating performance.

Example 4 The following laminated (three-layer laminated) heat insulating material was applied to a copper tube having an outer diameter of 15.9 mm and a wall thickness of 1 mm.

The three single-layer heat insulating materials obtained in Example 1 were used for lamination. One of the three tubes was cut so that the outer peripheral length of the copper tube and the length of the embossed side were almost the same. When the heat insulating material is wound on a tube, it is an inner layer that directly contacts the copper tube. The remaining two single-layered heat-insulating materials, which became outer layers when wound on a pipe, were gradually lengthened in the width direction so as not to be wrinkled when laminated and wound on the pipe, and cut. These three heat insulating materials having different lengths were sequentially bonded using an adhesive to obtain a laminated heat insulating material. The laminated heat insulating material was wound around the copper tube and fastened with an adhesive tape. As a result, a copper pipe having an outer diameter of about 40 mm formed by applying a heat insulating material was obtained.

Hot water was flowed through the copper tube provided with the heat insulating material, and the thermal conductivity of the heat insulating material was determined. The thermal conductivity was determined by measuring the temperature of the inner and outer surfaces of the heat insulating material and the temperature of the inlet and outlet of hot water. The temperature of the outer surface of the heat insulating material was 5 ° C, and the inner surface was 50 ° C. The effective thermal conductivity is 0.030 W /
Km.

Comparative Example 7 A flat polyethylene resin film (thickness: 10 μm) was further laminated on the embossed resin film (B) of the single-layer heat insulating material of Example 1 and adhered. A heat insulating material as a resin film (A) was produced. Next, in the same manner as in Example 4, three pieces of the heat insulating material, which were cut by gradually increasing the length in the width direction, were overlapped and installed on the pipe, but the flat resin film inside each heat insulating material ( A) was compressed and deformed, causing wrinkles. As a result, a portion having an outer diameter of about 42 mm (about 2 mm larger than that of Example 4) was formed. Therefore, when this pipe is passed through a wall, it is necessary to make a hole about 2 mm larger than the heat insulating material of the fourth embodiment.

The effective thermal conductivity was increased by about 7% compared to the heat insulating material of Example 4. This is considered to be a result of the occurrence of wrinkles where the space between the resin films was partially reduced, and the heat transfer by air at that portion was increased.

[Brief description of the drawings]

FIG. 1 is a diagram showing an example of the heat insulating material of the present invention (single-layer type) and a method of manufacturing the heat insulating material of the present invention.

FIG. 2 is a view showing an example of the heat insulating material of the present invention (single-layer type) in which aluminum is vapor-deposited on the outer surface of a film (B).

FIG. 3 is a view showing an example of the heat insulating material of the present invention (laminated type) and an example of applying the heat insulating material of the present invention to a pipe.

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 3H036 AA01 AB03 AB18 AB35 AC03 AE13 4F100 AA36B AB10C AB10D AH05B AK01A AK01B AK04A AK04B AK15A AK15B AK41A AK41B AK46A AK46B EK49 E03 E03B03E66

Claims (6)

[Claims] 1. A heat insulating material comprising two resin films in which a flat resin film (A) and an embossed resin film (B) are bonded, 1) a film (A) and a film (B) And (2) a resin film having an energy absorption rate of 0.1 or less for black body radiation at 0 to 100 ° C. is used. 2) The height of the embossed projections of the film (B) is 1 to 1
0) 3) Gas is sealed in the embossed projections of the film (B), 4) Aluminum is deposited on the outer surface of the film (A), 5) Film (A) after aluminum deposition ) On the inside surface,
A heat insulating material having an energy reflectance of 0.85 or more with respect to blackbody radiation at 0 to 100 ° C. 2. The heat insulating material according to claim 1, wherein aluminum is deposited on the outer surface of the film (B). 3. The heat insulating material according to claim 1, wherein the sealed gas is a gas containing at least one selected from the group consisting of carbon dioxide and fluorinated hydrocarbons. 4. The thermal insulation according to claim 1, wherein the material of the resin film is at least one selected from the group consisting of a polyimide resin, a polyester resin, a polyamide resin, a polyethylene resin and a polyvinyl chloride resin. Wood. 5. A film (A) of a heat insulating material, wherein at least two of the heat insulating materials according to claim 1 are used as one heat insulating material.
And a laminated heat insulating material for a tube, which is laminated so that the embossing of the film (B) of the other heat insulating material is in contact with the film, and the thickness direction so that both end surfaces are joined when applied to the pipe. A laminated heat insulating material for pipes, which is cut into gradually widened shapes. 6. A heat insulating material for a pipe, which is formed into a cylindrical shape by connecting both ends of the heat insulating material according to claim 5.